People (including me) are really starting to use the short array syntax. I don't really want to start this discussion, but unfortunately, we are also seeing examples of inconsistent code like:
I see that drupal have faced this issue and discussed it extensively too:
They have a section in their coding style which I think we should adopt something similar:
The use of PHP 5.4+ short array syntax for Drupal 8.x is being discussed and is used in some patches already. When used, try to apply it consistently to at least a whole method or function.
Looks like phpcs has a fixer for it, so thats an extremely invasive option to go wholesale into it.